Barry Bonds's Former Mistress Testifies At His Trial

Kimberly Bell is a key witness in the pre-jury trial of baseball legend Barry Bonds and is testifying in graphic detail about his alleged steroid use and the striking effects on his body.

"Bloating, acne on his back, losing of the hair. Dysfunction sexually," Bell said.

"Do you know for a fact that Barry Bonds knowingly used steroids?" INSIDE EDITION's Paul Boyd asked her in 2007.

"He told me he used steroids," Bell said.

Her testimony in a San Francisco court is almost exactly what she told INSIDE EDITON in our exclusive interview in 2007.

Bonds denies ever knowingly using steroids and pled not guilty to lying to a grand jury.

Bell was Bonds's mistress for nearly a decade. She says it was love at first sight.

"He was captured right away. He kind of looked at me and said 'You're mine,' and that's how it began," Bell told Boyd.

"You fell in love with him?" Boyd asked.

"Yeah I did," said Bell.

But she says she witnessed his body changing.

"He must have gained 20-30 pounds in a seven to eight month period. He looked like a linebacker," said Bell.

Bell, who posed for Playboy in 2007, told INSIDE EDITION Bonds was very self-conscious about his physical transformation.

"He would stand in the mirror, out of the shower with me and look at each other side by side and point out things on his body and ask me if it was obvious," Bell said.

She says he developed a hair-trigger temper that caused him to say mentally abusive things, which experts say is a side effect of steroid use.

In a recorded voicemail to Bell, Bonds says, "Slut, now I'm mad, because your [expletive] is supposed to be at home. I'll call you a little later after I do this commercial shoot but they said you were gone, so you better explain to me where the [expletive] you are!"

Bell says Bonds once threatened to kill her for being 20 minutes late for a date: "I was greeted with his hand on my throat and he twisted me around and pushed me against the wall and whispered in my ear, ‘If you ever do this again, I'll kill you.'"